Problem: Yasin and his twin brother Omar have both experienced very similar upbringings, as they grew up in the same family. Their family relocated to the U.S. as refugees after adverse experiences in their country due to war, including that their father was killed. Now that they are adults, Yasin is struggling with issues related to Major Depressive Disorder, and Omar finds more problems with being extremely shy and socially anxious. Which concept below is illustrated in this example?